#include <vector>
#include <algorithm>
using namespace std;

vector<int> differ(vector<int> initial,vector<int> target){
    int n = initial.size();
    vector<int> diff(n);
    // 排除不可能达到的目标
    if(n!=(int)target.size()){
        diff[0] = -1;
        return diff;
    }
    // 计算差异环
    for (int i = 0; i < n; ++i) {
        diff[i] = initial[i] ^ target[i];
    }
    return diff;
}